Feature request: session row action extension hook (so consumers don't fork SessionSidebar for copy/archive/etc.)

[dust617]

Summary

The session sidebar (SessionSidebar.tsx) has no extension hook for per-row actions. Downstream consumers that want to add row actions (copy session ID/path, archive/unarchive, star, etc.) are forced to fork and modify the component internals — which breaks on every upstream change and makes upgrades fragile.

Problem

Because there is no row-action API, downstream projects duplicate the whole SessionSidebar rendering logic just to add a right-click menu or a couple of buttons per session row. This creates:

• Large, upgrade-fragile downstream patches (a downstream fork currently patches ~200 lines of SessionSidebar.tsx).
• No way to contribute features without diverging from upstream.
• Duplicated session-tree / context-menu logic in every consumer.

Suggested API

A stable, minimal surface would be:

1. A session-row-action extension event/bus that fires with the session id/path (the extension system already exists via pi.on(...)).
2. Or a per-row action render slot that consumers opt into via a prop.

Value

• Removes the need to fork SessionSidebar.tsx for row actions (largest downstream patch today).
• Makes feature contributions (archive, copy, star, pin) portable extensions instead of forks.
• Eases every future upstream upgrade for downstream consumers.

Environment

• pi-web 0.8.7
• Reported from a downstream Electron wrapper that currently patches SessionSidebar.tsx to add copy + archive row actions.